Not quite following the approach used as it seems to indicate *it is* tag related. In any case, one can see the issues using the following approach:
1. Create two types of test albums: same artist album, multi-artist album (soundtrack, compilation).
2. Using a "comprehensive" tag editing application, remove all ID3Tag (frame) details.
3. Ensure that iTunes (Windows/Mac) settings/preferences are set to *not* obtain any ID3Tag details from external sources - i.e. disable all query, ratings, etc. Ideally, a new/clean/empty library on the latest version of iTunes.
4. Drag-and-drop the test albums to the "Automatically Add To iTunes" folder. Observe the results, review the tracks using "Get Info". Then purge the test albums.
5. Drag-and-drop the test albums directly to the iTunes Library - i.e. into the UI window. Observe the results, review the tracks using "Get Info".
6. Sync a iDevice (iPhone/iPad) running iOS 11.4 and observe the results in the iDevice Music app. Ideally, a new/clean/empty library on the latest version of iTunes. Ensure the iDevice Music app settings are set to *not* obtain ID3Tag details from external sources.
TEST 1
What are the results of using "Get Info" to populate the ID3Tag details. Populate "Song" - i.e. not switching to "Work Name".
TEST 2
What are the results of populating the fields that appear when "Work Name" is selected.
TEST 3
Using a "comprehensive" tag editing application, examine the ID3Tag details of the files in the iTunes Media folder. Not reported ID3Tag implementation (ex: ID3v1, ID3v2, etc.). Quit iTunes and use the tag editing application to alter these tags to include additional fields that are present in ID3v2, then editing again to include additional fields in ID3v4, etc.
Relaunch iTunes and observe the results in iTunes, cleanup the iDevice, copy the files back to the iDevices and observe the results.
TEST 4
Copy the test albums found in the iTunes Music folder elsewhere - i.e. iTunes version of the test albums. Remove the test albums from iTunes. Cleanup the iDevice - i.e. clean iDevice library.
Drag-and-drop the original test albums to the iDevice via the iTunes UI. Observe the results.
Drag-and-drop the iTunes version of the test albums to the iDevice via the iTunes UI. Observe the results.